iOS/Android: There's certainly no shortage of apps that promise to let you send secure texts, photos, and more and then delete them from the recipient's phone later, but Wiper is one of the first to do that and add in encrypted voice calls. It's free, and you can control when the messages you've sent get erased.

Android/iOS: Previously mentioned Burner, an app for throwaway, disposable phone numbers that can be used for private calls and texts with anyone you might not want to have your real contact info, used to be iPhone only. Now the app is available for Android too, and both versions have new features like customizable…

Android (4.0+): Hushed generates disposable, throw-away phone numbers that you can use for incoming and outgoing phone calls and SMS. The app is ideal for communicating with anyone you don't necessarily want to have your number, like the person you're selling old furniture to on Craigslist or a blind date you're…